Search results for "temperature measurement"
showing 10 items of 123 documents
Cheap Sensor Made of Multicrystalline Silicon for Insolation and Temperature Measurements
2016
Abstract In the paper some results on measurement of insolation and „real” cell’s temperature carried out with use of standard silicon solar cells are presented. Two identical cells are applied in such a sensor. Short circuit current of one cell is a direct indication of insolation value and open circuit voltage of the other cell is indirect indication of actual sensor’s temperature but in this case more complex formula must be used for temperature calculation.
A broadening temperature sensitivity range with a core-shell YbEr@YbNd double ratiometric optical nanothermometer.
2016
The chemical architecture of lanthanide doped core–shell up-converting nanoparticles can be engineered to purposely design the properties of luminescent nanomaterials, which are typically inaccessible to their homogeneous counterparts. Such an approach allowed to shift the up-conversion excitation wavelength from ∼980 to the more relevant ∼808 nm or enable Tb or Eu up-conversion emission, which was previously impossible to obtain or inefficient. Here, we address the issue of limited temperature sensitivity range of optical lanthanide based nano-thermometers. By covering Yb–Er co-doped core nanoparticles with the Yb–Nd co-doped shell, we have intentionally combined temperature dependent Er u…
EU dissemination of the provisional ultra-low-temperature scale, PLTS-2000
2003
Following the introduction of the provisional low-temperature scale from 0.9 mK to 1K, PLTS-2000, there is a need for primary and secondary thermometers and fixed points, which can disseminate the scale to users. This paper reports on the progress, within the EU collaborative project ‘ULT Dissemination’, in the development and evaluation of several devices with associated instrumentation. Principal among them are a current-sensing noise thermometer, a CMN thermometer adapted for industrial use, a Coulomb blockade thermometer, a second-sound thermometer, a 3He melting pressure thermometer for a direct realisation of the PLTS-2000. A superconductive reference device has also been developed, a…
Weld pool surface temperature measurement from polarization state of thermal emission
2014
This paper presents a passive polarimetry method using a division of aperture optical device in order to measure the temperature distribution at the weld pool surface. Thermal emission from a hot liquid metal was investigated at a near-infrared wavelength corresponding to a blind spectral window of a helium plasma generated during gas tungsten arc welding process. The refractive index of liquid metal and the surface radiance are deduced from the polarisation state of thermal emissions. Based upon the knowledge of both characteristics, the temperature distribution can be calculated. Conseil Régional de Bourgogne
Closing the sensing-reasoning-actuating loop in resource-constrained WSANs through distributed symbolic processing
2015
Many issues in creating complex applications for pervasive environments are primarily due to the effort required to integrate perception, reasoning and actuating tasks in an efficient and homogeneous way, especially when the underlying infrastructure consists of wirelessly networked embedded devices. To mitigate the complexity of the actual implementation, satisfactory programming paradigms supporting the integration and coordination among heterogeneous devices are required. In this paper we show how a distributed symbolic processing approach that is particularly suited for resource constrained devices, such as the nodes of a Wireless Sensor and Actuator Network (WSAN), may be apt to the pu…
ALD thin ZnO layer as an active medium in a fiber-optic Fabry–Perot interferometer
2015
Abstract A novel optical fiber sensor of temperature using a thin ZnO layer fabricated by atomic layer deposition (ALD) is demonstrated for the first time. The thin ZnO layer was grown on the face of a standard optical telecommunication fiber SMF-28 and operates as a Fabry–Perot interferometer sensitive to temperature. The interferometer characterization was made in the temperature range extending from 50 to 300 °C with resolution equal to 1 °C. The output signal was analyzed by measurement of the shift of the maxima in spectral pattern. The sensitivity of temperature measurement is about 0.05 nm/°C. Furthermore, very good linearity of the sensor was achieved with correlation coefficient R2…
The methane Raman spectrum from 1200 to 5500 cm(-1): A first step toward temperature diagnostic using methane as a probe molecule in combustion syste…
2005
International audience; We present a study of the spontaneous Raman spectra of (CH4)-C-12 from 1200 to 5500 cm(-1) at various temperatures. This study is of interest from a fundamental as well as from a practical point of view with regards to the temperature diagnostic in hydrocarbon combustion. The present investigation shows that the spontaneous (CH4)-C-12 Raman spectra are very sensitive to temperature and that the complexity of methane spectra is not an obstacle to use methane as a probe molecule in laser-diagnostic techniques. Our study consists in determining the polarisability parameters of methane (CH4)-C-12, unknown at the present time, from spontaneous Raman spectra recorded at pr…
Finite difference analysis of the thermal behaviour of coated tools in orthogonal cutting of steels
2004
Abstract Temperature measurement and prediction have been a major focus of machining for several decades but now this problem became more important due to the wider use of advanced cutting tool coatings. Practically, there is a lack of simulation programs for prediction of the temperatures in the cutting zone when machining with differently coated cutting tools. In all literature items cited the finite difference methods (finite difference approaches) were used to find the distribution of temperature inside the uncoated tool body or along the tool–chip interface for continuous (turning) and interrupted (milling) machining processes. The algorithm applied overcomes this limit. In this study,…
A field method for measuring the thermal infrared emissivity
1993
Abstract In this work, a field method for measuring thermal infrared emissivities is proposed which is based on the box method, initially developed by Buettner and Kern (1965) for laboratory measurements. A theoretical analysis was made of the measurement carried out using the box and a correcting factor to Buettner and Kern's technique has been determined. Buettner and Kern's method has been modified to use radiative temperatures measured with a radiothermometer instead of radiance measurements. The walls of the box used and the cold lid was made of polished aluminium and the hot lid was made of black-painted anodized aluminium and it was heated in the field by solar radiation. With this m…
CARS methane spectra: Experiments and simulations for temperature diagnostic purposes
2007
International audience; CARS laboratory experiments were done in the 2905-2925 cm(-1) range, in the vicinity of the v, band of the methane molecule, for pressures ranging from I to 50 bar, and temperatures up to 1100 K. These experiments were carried out in order to retrieve the pressure evolution of the CH4 spectrum, as well as to confirm its temperature dependance. After a brief recall on the theory used to compute pressure broadening coefficients and relaxation rates, we consider the v(3) and v(4) infrared bands of methane for benchmark calculations purposes. Next, we present recent experimental CARS spectra and calculated ones. Lastly, we discuss flame experiments as well as comparisons…